Ota Tofu is at SE 8th or 9th and Stark near the mini mall, and is the freshest I've found.

You can also buy fresh tofu by the block at the Alberta Coop, People's Coop, probably Proper Eats, and as Celyn mentioned, Bui Tofu who make their own, Thanh Son on 82nd a block or two above E Burnside (I prefer this one, location wise it's easiest for me, and they have fun flavored tofu, too, like lemongrass and chili garlic) and out at JC Rice Noodle on SE Foster.